import type { WebGLRenderTarget } from "three";
import * as THREE from "three";
import type { SceneCollection } from "./App";
import Config from "./Config";

interface Resources {
    worldRenderTarget: THREE.WebGLRenderTarget;
    worldRenderTargetCopy: THREE.WebGLRenderTarget;
    worldBlurredRenderTarget: THREE.WebGLRenderTarget;
    antsDataRenderTarget0: THREE.WebGLRenderTarget;
    antsDataRenderTarget1: THREE.WebGLRenderTarget;
    antsDiscreteRenderTarget: THREE.WebGLRenderTarget;
}

export default class Renderer {
    private renderer: THREE.WebGLRenderer;
    public resources!: Resources;

    constructor(public canvas: HTMLCanvasElement) {
        this.renderer = new THREE.WebGLRenderer({ canvas });

        this.initResources();
    }

    private initResources() {
        const antTextureSize = Math.round(Math.sqrt(2 ** Config.antsCount));

        this.resources = {
            worldRenderTarget: new THREE.WebGLRenderTarget(
                Config.worldSize,
                Config.worldSize,
                {
                    format: THREE.RGBAFormat,
                    type: THREE.FloatType,
                    depthBuffer: false,
                    magFilter: THREE.LinearFilter,
                    minFilter: THREE.LinearFilter,
                },
            ),
            worldRenderTargetCopy: new THREE.WebGLRenderTarget(
                Config.worldSize,
                Config.worldSize,
                {
                    format: THREE.RGBAFormat,
                    type: THREE.FloatType,
                    depthBuffer: false,
                    magFilter: THREE.NearestFilter,
                    minFilter: THREE.NearestFilter,
                },
            ),
            worldBlurredRenderTarget: new THREE.WebGLRenderTarget(
                Config.worldSize,
                Config.worldSize,
                {
                    format: THREE.RGBAFormat,
                    type: THREE.FloatType,
                    depthBuffer: false,
                    magFilter: THREE.NearestFilter,
                    minFilter: THREE.NearestFilter,
                },
            ),
            antsDataRenderTarget0: new THREE.WebGLRenderTarget(
                antTextureSize,
                antTextureSize,
                {
                    format: THREE.RGBAFormat,
                    type: THREE.FloatType,
                    depthBuffer: false,
                    magFilter: THREE.NearestFilter,
                    minFilter: THREE.NearestFilter,
                },
            ),
            antsDataRenderTarget1: new THREE.WebGLRenderTarget(
                antTextureSize,
                antTextureSize,
                {
                    format: THREE.RGBAFormat,
                    type: THREE.FloatType,
                    depthBuffer: false,
                    magFilter: THREE.NearestFilter,
                    minFilter: THREE.NearestFilter,
                },
            ),
            antsDiscreteRenderTarget: new THREE.WebGLRenderTarget(
                Config.worldSize,
                Config.worldSize,
                {
                    format: THREE.RGBAFormat,
                    type: THREE.UnsignedByteType,
                    depthBuffer: false,
                    magFilter: THREE.NearestFilter,
                    minFilter: THREE.NearestFilter,
                },
            ),
        };
    }

    public renderSimulation(scenes: SceneCollection) {
        const [antsComputeSource, antsComputeTarget] =
            scenes.ants.getRenderTargets();

        this.setViewportFromRT(this.resources.worldBlurredRenderTarget);
        this.renderer.setRenderTarget(this.resources.worldBlurredRenderTarget);
        scenes.worldBlur.material.uniforms.tWorld.value =
            this.resources.worldRenderTarget.texture;
        this.renderer.render(scenes.worldBlur, scenes.worldBlur.camera);

        this.setViewportFromRT(antsComputeTarget);
        this.renderer.setRenderTarget(antsComputeTarget);
        scenes.ants.material.uniforms.tLastState.value =
            antsComputeSource.texture;
        scenes.ants.material.uniforms.tWorld.value =
            this.resources.worldBlurredRenderTarget.texture;
        this.renderer.render(scenes.ants, scenes.ants.camera);

        this.setViewportFromRT(this.resources.antsDiscreteRenderTarget);
        this.renderer.setRenderTarget(this.resources.antsDiscreteRenderTarget);
        scenes.discretize.material.uniforms.tDataCurrent.value =
            antsComputeTarget.texture;
        scenes.discretize.material.uniforms.tDataLast.value =
            antsComputeSource.texture;
        this.renderer.render(scenes.discretize, scenes.discretize.camera);

        this.setViewportFromRT(this.resources.worldRenderTarget);
        this.renderer.setRenderTarget(this.resources.worldRenderTarget);
        scenes.world.material.uniforms.tLastState.value =
            this.resources.worldBlurredRenderTarget.texture;
        scenes.world.material.uniforms.tDiscreteAnts.value =
            this.resources.antsDiscreteRenderTarget.texture;
        this.renderer.render(scenes.world, scenes.world.camera);

        scenes.screen.material.uniforms.tData.value = antsComputeTarget.texture;
        scenes.screen.groundMaterial.uniforms.map.value =
            this.resources.worldRenderTargetCopy.texture;
    }

    private setViewportFromRT(rt: WebGLRenderTarget) {
        this.renderer.setViewport(0, 0, rt.width, rt.height);
    }

    public renderToScreen(scenes: SceneCollection) {
        this.setViewportFromRT(this.resources.worldRenderTargetCopy);
        this.renderer.setRenderTarget(this.resources.worldRenderTargetCopy);
        scenes.draw.material.uniforms.tWorld.value =
            this.resources.worldRenderTarget.texture;
        scenes.draw.material.uniforms.pointerPosition.value =
            scenes.screen.pointerPosition;
        scenes.draw.material.uniforms.drawMode.value = scenes.screen.drawMode;
        scenes.draw.material.uniforms.brushRadius.value = Config.brushRadius;
        this.renderer.render(scenes.draw, scenes.draw.camera);
        this.renderer.copyFramebufferToTexture(
            this.resources.worldRenderTarget.texture,
            new THREE.Vector2(),
        );

        this.renderer.setViewport(
            0,
            0,
            scenes.screen.renderWidth,
            scenes.screen.renderHeight,
        );
        this.renderer.setRenderTarget(null);
        this.renderer.render(scenes.screen, scenes.screen.camera);
    }

    public resizeCanvas(width: number, height: number) {
        this.canvas.width = width;
        this.canvas.height = height;
    }

    public getCommonMaterialDefines(): Record<string, string> {
        return {
            WORLD_SIZE: Renderer.convertNumberToFloatString(Config.worldSize),
            SCENT_THRESHOLD: Renderer.convertNumberToFloatString(
                Config.scentThreshold,
            ),
            SCENT_FADE_OUT_FACTOR: Renderer.convertNumberToFloatString(
                Config.scentFadeOutFactor,
            ),
            SCENT_BLUR_RADIUS: Renderer.convertNumberToFloatString(
                Config.scentBlurRadius,
            ),
            SCENT_MAX_STORAGE: Renderer.convertNumberToFloatString(
                Config.scentMaxStorage,
            ),
            SCENT_PER_MARKER: Renderer.convertNumberToFloatString(
                Config.scentPerMarker,
            ),
            SCENT_MAX_PER_CELL: Renderer.convertNumberToFloatString(
                Config.scentMaxPerCell,
            ),
            ANT_SPEED: Renderer.convertNumberToFloatString(Config.antSpeed),
            ANT_ROTATION_ANGLE: Renderer.convertNumberToFloatString(
                Config.antRotationAngle,
            ),
        };
    }

    public reset(scenes: SceneCollection) {
        const antTextureSize = Math.round(Math.sqrt(2 ** Config.antsCount));

        this.resources.worldRenderTarget.setSize(
            Config.worldSize,
            Config.worldSize,
        );
        this.renderer.setRenderTarget(this.resources.worldRenderTarget);
        this.renderer.clear();

        this.resources.worldRenderTargetCopy.setSize(
            Config.worldSize,
            Config.worldSize,
        );
        this.renderer.setRenderTarget(this.resources.worldRenderTargetCopy);
        this.renderer.clear();

        this.resources.worldBlurredRenderTarget.setSize(
            Config.worldSize,
            Config.worldSize,
        );
        this.renderer.setRenderTarget(this.resources.worldBlurredRenderTarget);
        this.renderer.clear();

        this.resources.antsDataRenderTarget0.setSize(
            antTextureSize,
            antTextureSize,
        );
        this.renderer.setRenderTarget(this.resources.antsDataRenderTarget0);
        this.renderer.clear();

        this.resources.antsDataRenderTarget1.setSize(
            antTextureSize,
            antTextureSize,
        );
        this.renderer.setRenderTarget(this.resources.antsDataRenderTarget1);
        this.renderer.clear();

        this.resources.antsDiscreteRenderTarget.setSize(
            Config.worldSize,
            Config.worldSize,
        );
        this.renderer.setRenderTarget(this.resources.antsDiscreteRenderTarget);
        this.renderer.clear();

        for (const scene of Object.values(scenes)) {
            scene.recompileMaterials();
        }
    }

    static convertNumberToFloatString(n: number): string {
        return n.toFixed(8);
    }
}